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Touch circuit sound, led. 555 timer

9 months ago I got some help from a few members designing and breadboarding this project. Im new but I'm also determined. With this groups help I have completed other projects too. What this does is open a relay and beep when a sensor is touched. Touch again and it repeats and closes the relay. If will however close the relay on its own after 10-15 miniutes if not manually done. Member eTech helped me with this and i appreciate it. Well I put it together and gave it power. Only the power led and the standby led work. I HAVE studied the breadboard and it does appear correct. I laid it out very neatly so you may be able to see what i may have missed.. I need help now figuring out what is wrong. Thank you in advance. Ive provided the breadboard and schematic in PDF.
 

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eTech

Well-Known Member
9 months ago I got some help from a few members designing and breadboarding this project. Im new but I'm also determined. With this groups help I have completed other projects too. What this does is open a relay and beep when a sensor is touched. Touch again and it repeats and closes the relay. If will however close the relay on its own after 10-15 miniutes if not manually done. Member eTech helped me with this and i appreciate it. Well I put it together and gave it power. Only the power led and the standby led work. I HAVE studied the breadboard and it does appear correct. I laid it out very neatly so you may be able to see what i may have missed.. I need help now figuring out what is wrong. Thank you in advance. Ive provided the breadboard and schematic in PDF.
Hi

Does it work without the touch sensor? What is the touch sensor part number?

What troubleshoot tools do you have?
 
I've got a mm.
How would I bypass the touch sensor? Hook up a switch button to positive?
Thank you for helping. Good to hear from you.
 

eTech

Well-Known Member
Just to let you know....I still have it bread boarded from the last time we communicated.
It worked after I powered it up. :)

1. Its hard to tell the IC orientation from the photo. Can you identify the "notch" end of the each chip?
2. Also call out the chip name (ie, CD4013) just as a crosscheck.
3. What tools do you have to troubleshoot with? Scope? Multimeter?
oh....you have a multimeter...good.
4. Before we get started, I'd like to check your breadboard wiring and components.
 

eTech

Well-Known Member
So far....

1. missing jumper at VR1. (if its there, I cant see it).
2. I see you used the "alternate circuit", Q10, Q9. I cant remember, at the moment, why that was offered. I didn't use that part of the circuit on my bench circuit.
But I believe Q10, Q9 collector and emitter are swapped. So I think that part of the circuit needs to be rewired and checked.
Who is the manufacture of the BJT's? so we can verify them against the datasheet.

However, we need to test the rest of the circuit without that part of the circuit connected anyway.
If you have a small momentary n.o. switch, disconnect the wire at Q10 (to junction C13/R5), then connect one end to the junction of C13/R15, the other end to +5v. Then when the switch is pressed, it should cause the 4013(toggle) to toggle.

We'll use a "divide and conquer" testing approach. Once we get this part of the circuit working, we'll move to the next portion of the circuit.
 
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missing jumper at VR1. (if its there, I cant see it).
2. I see you used the "alternate circuit", Q10, Q9. I cant remember, at the moment, why that was offered. I didn't use that part of the circuit on my bench circuit.
But I believe Q10, Q9 collector and emitter are swapped. So I think that part of the circuit needs to be rewired and checked.
Who is the manufacture of the BJT's? so we can verify them against the datasheet.
Ok the jumper missing.
It looks correct. Resistor starts at + then to vr1, then to cap then to ground. In between vr1 and c1 is a jumper (yellow) that goes to pin6 of 555.
Q10,q9 it looks like I just need to turn them around correct. As far as the manufacture it is unknown.
The alternate circuit was to boost the voltage to compensate for the long distance between the touch pad and the module here.
I have removed the touch pad. Replaced with a pair of jumper wires. Ill give this a test in a few.
 
However, we need to test the rest of the circuit without that part of the circuit connected anyway.
If you have a small momentary n.o. switch, disconnect the wire at Q10 (to junction C13/R5), then connect one end to the junction of C13/R15, the other end to +5v. Then when the switch is pressed, it should cause the 4013(toggle) to toggle.
I will do this next. I need to tend to my fam for a while. Ill return tomorrow.
 

eTech

Well-Known Member
Ok the jumper missing.
It looks correct. Resistor starts at + then to vr1, then to cap then to ground. In between vr1 and c1 is a jumper (yellow) that goes to pin6 of 555.
Q10,q9 it looks like I just need to turn them around correct. As far as the manufacture it is unknown.
The alternate circuit was to boost the voltage to compensate for the long distance between the touch pad and the module here.
I have removed the touch pad. Replaced with a pair of jumper wires. Ill give this a test in a few.
I mean there should be a small jumper from the middle pin of VR1 to one of its outer pins. That configures it as a variable resistor rather that a pot.
We want it to be a variable resistor.
 
That configures it as a variable resistor rather that a pot.
Interesting. I did not know that. I thought you just used the center pin and one of the outer pins and that's it. But instead you do use all 3 pins.
So r6 connects to pin 1 of vr1 then pin 3 connects to c1+. Pin 2 of vr1 connects to pin 1 or 3. Cool. Thank you.
 
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